1. Field
The subject matter disclosed herein relates to the collection and/or processing of sensor data from multiple sensors.
2. Information
A variety of sensors are available to support a number of applications in today's market. These sensors may convert physical phenomena into analog and/or electrical signals. Such sensors may include, for example, a barometric pressure sensor. A barometric pressure sensor may be used to measure atmospheric pressure. Applications for the barometric pressure sensor may include determining altitude. Other applications may include observing atmospheric pressure as it relates to weather conditions.
Another sensor type may include an accelerometer. An accelerometer may sense the direction of gravity and any other force experienced by the sensor. The accelerometer may be used to sense linear and/or angular movement, and may also be used, for example, to measure tilt and/or roll.
Yet another sensor type may include a gyroscope which measures the Coriolis effect and may be used in applications measuring heading changes or in measuring rate of rotation. Gyroscopes have, for example, important applications in the field of navigation.
Another type of sensor may include a magnetic field sensor that may measure the strength of a magnetic field and, correspondingly, the direction of a magnetic field. A compass is an example of a magnetic field sensor. The compass may find use in determining absolute heading in car and pedestrian navigation applications.
Biometric sensors represent another type of sensors that may have a variety of possible applications. Some examples of biometric sensors may include heart rate monitors, blood pressure monitors, fingerprint detection, touch (heptic) sensors, blood sugar (glucose) level measuring sensors, etc.
The above sensors, as well as other possible sensors not listed, may be utilized individually or may be used in combination with other sensors, depending on the particular application. For example, in navigation applications, accelerometers, gyroscopes, geomagnetic sensors, and pressure sensors may be utilized to provide adequate degrees of observability. For one example, the accelerometer and gyroscope may provide six axes of observability (x, y, z, τ, φ, ψ). As mentioned above, the accelerometer may sense linear motion (translation in any plane, such as a local horizontal plane). This translation may be measured with reference to at least one axis. The accelerometer may also provide a measure of an object's tilt (roll or pitch). Thus, with the accelerometer, an object's motion in Cartesian coordinate space (x, y, z) may be sensed, and the direction of gravity may be sensed to estimate an object's roll and pitch. The gyroscope may be used to measure the rate of rotation about (x, y, z), i.e., roll (τ) and pitch (φ) and yaw, which may also be referred to as azimuth or “heading” (ψ).
Navigational applications are merely one example of how more than one sensor type may be utilized in combination to provide multi-axes measurement capabilities. The utilization of multiple sensors to perform measurements may present a number of challenges to users of these devices. Such challenges may include, for example, size, cost, interfaces, connectivity, and/or power consumption of the multiple sensors.